Process for molding building slabs in position



March 6, 1951 R. w. RUMBLE PROCESS FOR MOLDING BUILDING SLABS IN PosmouFiled April 11, 1947 xwveu-rok.

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Patented Mar. 6 1951 PROCESS FOR MOLDING BUILDING SLABS IN POSITION RoyWilliam Rumble, Pretoria, Transvaal, Union of South Africa ApplicationApril 11, 1947, Serial No. 740,902

In the Union of South Africa April 16, 1946 The invention relates to aprocess for moulding in position a concrete building slab that issupported by vertically-extending structure the upper portion of whichis incorporated into the slab when the latter is moulded; said slabhaving a considerable horizontal component of direction, such as a flooror ceiling or roof slab that is completely horizontal, or a pitched roofslab that is inclined to the horizontal. The term concrete is used inthis. specification to mean any appropriate building material that ismoulded in a plastic condition and, being then caused or allowed to set,becomes solid building material.

A process of forming a concrete building slab in position, according tothis invention, comprises the erection on a rigid base of structurevertically-extending upwards from the base and suitable to support theslab permanently and comprising elements which are spaced apart in plansuitably for deck shuttering to be placed between them in position forthe slab to be moulded on it and with at least the major verticalextent, and preferably the upper extremity of the verticallyextendingstructure in the moulding space; said vertically-extending structurebeing suitable also to permit the deck shuttering to be lowered fromsaid moulding position. Means for supporting the deck shuttering in saidmoulding position are detachably attached to the vertically-extendingstructure; and the deck shuttering is rested on said supporting means.The slab is then poured and incorporates said upper extremity of thevertically-extending structure permanently in the slab. Thereafter theerected shuttering is dismantled by a procedure including displacementof the supporting means to allow the deck shuttering to be dropped fromthe slab while the vertically-extending structure is left in position.

shuttering according to this invention, for moulding a concrete buildingslab in position comprises the above described vertically-extendingstructure, deck shuttering placed between the ele ments of thevertically-extending structure and in position for the slab to bemoulded on it and for at least the major vertical extent and preferablythe upper extremity of the vertically-extending structure to be in themoulding space, said structure permitting the deck shuttering to belowered from said moulding position. The shuttering further includesmeans detachably attached to the vertically-extending structure beneaththe deck shuttering in position for sustaining the deck shuttering insaid moulding position.

Also according to this invention, the vertically- 2 Claims. (01. 25-154extending structure is erected on a concrete base in which its lowerextremity is incorporated bytheir upper ends positioned in the mouldingspace for the slab. The upper ends of said rodlike elements arepreferably disposed, in plan view, in parallel rows between which thedeck shuttering isplaced.

A convenient means for supporting the deck shuttering in its mouldingposition comprises cleats temporarily clamped to the rod-like elements.

The invention is illustrated by the accompanying drawings, which showssuccessive stages in the construction of the concrete roof slab of apitched roof.

2 indicates a ceiling slab which is moulded in place with the aid ofremovable deck shuttering 3. Before said slab is moulded,verticallyextending structure 4 is placed in the position where itslower portions are within the space to be occupied by the slab material;so that said lower portion becomes incorporated in the fin ished ceilingslab.

The vertically-extending structure 4 show consists of a number oftruss-like units 5 each formed by bending a length of concretereinforcing barv back and forth in one plane to form a series of legs 5united to one another by lower and upper bends marked 6a and 6brespectively, and sloping alternately one way and the other. Said units5 are positioned parallel with one another so that the upper bends (ibform parallel rows between which the deck shuttering 9 fits. When theroof slab l is cast at a later stage, said units 5 form the means bywhich the roof slab 1 is supported by and above the ceiling slab 2, andspaced from and united to the latter. With that object, the upper bends6b of the truss-like unit are incorporated into the material of the roofslab 1 when that slab is cast.

Before that occurs, the units 5 are made use of as part of theshuttering for the roof slab. The legs 6 form convenient means fortemporarily clamping thereto pairs of cleats 8 which constitute adequatetemperoary supports for the deck shuttering 9 on which the roof slab iis actually cast. When the ceiling slab 2 has set and the units 5 haveconsequently become firm in their upright position, the cleats 8 of eachpair are placed at the opposite sides of a pair of the legs 6 and areclamped in position by means of a through bolt ill. The cleats 8 arepositioned below the upper bends 6b sufiiciently to cause said bends tobe the space to be occupied by the roof slab 1. The deck shuttering9wide enough to span the distance between a pair of adjacent units 5--islaid on the cleats 8, and thin metal slips 13 are placed to cover thegaps it between the panel edges caused by the legs 6 coming betweenthem.

Means such as H having been placed for moulding the edge I2 of the roofslab 1, the roof slab l is cast; incorporating the upper bends 6b intoitself. After the slab '1 has set, the cleats 8 are loosened, allowingthe deck shuttering 9 to drop at least sufiiciently to part from theslab I. The fact that the units 5 lie in parallel vertical planes,allows the deck shuttering to drop that distance without obstruction.The cleats 8 and deck shuttering 9 are then removed from the now coveredroof cavity [4. One convenient exit for the deck shuttering is a gap I5left between the slabs l and 2 at the eaves; which gap need notnecessarily be filled in.

The completed roof is left; consisting of the ceiling slab, the roofslab and the units 5 uniting and spacing said slabs.

I claim:

1. The process of forming a concrete roof slab in position, whichconsists in first moulding a concrete base in position; during suchmoulding operation immovably embedding in the base so as to bepermanently embedded therein the lower ends of a series of verticallyextending rod-like elements suitable to support shuttering temporarilyand the slab permanently and which are spaced apart in plan suitably fordeck shuttering to be placed between them in position for the slab to bemoulded on it and suitably also for the shuttering to be lowered fromthe moulding position; detachably attaching to the elements means forsupporting the shuttering in the moulding position after the base hasset, resting the shuttering on the supporting means and pouring theslab; and dismantling the erected shuttering by a procedure includingdisplacement of the supporting means to allow the deck shuttering to bedropped from the slab leaving the elements in position supporting theslab.

2. The process claimed in claim 1 in which the base is a ceiling slab.

ROY WILLIAM RUMBLE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

